Devices have been used previously to secure electrical cable/conduit to an electrical junction box. One or more connectors must be provided for terminating the conduit or the various types and sizes of cable in accordance with the National Electrical Code (NEC).
The devices of Bridgeport Fittings catalog numbers 570-DC2 and 230-DC2 have a flexible flange built into an aperture in the junction box, or have an arrangement on a separate cable/conduit end connector that is then attached by a threaded end and nut.
U.S. Pat. No. 7,854,627 to Gretz discloses an electrical fitting with internal cable retainer. The electrical fitting has a trailing end with an arrangement for securing electrical cables thereto. The cable retainer includes a tubular body constructed of spring steel. A single cable retaining tang extends inwardly from a flat portion of the tubular body. The cable retainer can be connected to an junction/outlet box. The cable is retained at a location outside of the outlet box and the retainer is then connected to the junction/outlet box. This involves multiple steps in providing the connection and presents problems with regard to redoing the connection.
U.S. Pat. No. 7,703,813 to Kiely discloses a fitting connector or snap-in locking ring connector that connects in an aperture on the junction (outlet) box. The cable is retained at a location outside of the outlet box and the retainer is then connected to the junction/outlet box. Extra labor and material expense is involved in attaching an extra piece to a cable/conduit and then to the junction box.
Thomas & Betts catalog number 4-SDW-MXN shows a mechanism previously used that provides a junction box with internal clamping means. This device and others are limited to securing that same size and the same types of cable thereby requiring multiple junction boxes. U.S. Pat. No. 6,521,833 to DeFreites provides a device for use with corrugated plastic conduit. U.S. Pat. No. 5,728,971 to Nash requires a mounting locking mechanism outside of the junction/outlet box that is inserted into a slotted hole rather than the industry standard round hole. U.S. Pat. No. 4,845,312 to Lee is for use with threaded rigid conduit. U.S. Pat. No. 4,103,101 to Maier requires a special connector and a box combination. U.S. Pat. No. 1,131,399 to McGinley also requires special connector and box combination.
Difficulties with such attachment devices have occurred due to improper tightening of threaded nut or failure to fully engage the snap-in locking ring, both situations could result in improper bonding and securing of the cable/conduit to the junction box as required by the NEC.